Method of calculation improves by introducing the sound velocity of two phase flow into the equation for the vapor to liquid volume ratio. Comparisons of required net positive suction head and thermodynamic suppression head are made for a head coefficient ratio of 0.98

Kageyama, Y.

English

NASA Technical Reports Server

July 1971	 Brief 71-10239 
NASA TECH BRIEF 
Marshall Space Flight Center 	
_4V 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial' application. Tech Briefs are available on a aubscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the. Tech Brief program may 
be directed to the Technology Utilization Offi ce, NASA, Code KT, Washington, D. f. 20546. 
Improved Method for Calculating Pump Thermodynamic 
Suppression Head 
.
The thermodynamic effects in a pump inlet, termed 
the "thermodynamic suppression head" (TSH), were 
studied analytically and compared with experimental 
values. TSH is a significant effect which must be 
considered when fluid pumps and flow components 
are designed for cryogenic temperature operation. The 
method of calculating.TSH was improved by intro-
ducing the sound velocity of two-phase flow into the 
equation for the vapor-to-liquid volume ratio. Com- 
parisons between the calculated and experimental 
values of the required net positive suction heald 
(NPSH) and the TSI-I were made for a head co-
efficient ratio of 0.98. Calculation charts useful in 
evaluating the TSH are provided for oxygen, hydro-
gen, nitrogen, water and Freon 114. 
For oxygen pumps, a good agreement was obtained 
between the calculated and measured values of 
required NPSH over the range of liquid oxygen 
temperature, and considerably better agreement was
obtained for the TSH when the sound velocity 
in two-phase flow was included in the equation of 
the vapor-to-liquid volume ratio. Similar results were 
obtained for the water and hydrogen pumps. 
Note: 
Requests for further information may be directed 
to:
Technology Utilization Officer 
Code A&TS-TU 
Marshall Space Flight Center 
Huntsville, Alabama 35812 
Reference: B71-10239 
Patent status: 
No patent action is contemplated by NASA. 
Source: Y. Kageyama 
Marshall Space Flight Center
(MFS-20852) 
Category 07 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
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Improved method for calculating pump thermodynamic suppression head

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